Polymerization of hydrocarbon gases



Aug. 3,1937. y "c la'.` WAGNER 2088,824 PoLmEnIzATIoN 'oF HYnRocAnoNGASES Filleid pril 11, `1929 22191? lgjzer a@ WMM y liquids suitable foruse as gasoline. It will be understood, however, thatthe presentinvention may be operated in connection with gases obtained from othersources than cracking plants i .5 and I contemplate the application ofthe invention to all such additional uses.

The line I leads preferably to anaccumulator tank 2 having a liquiddraw-oi! line 2 inthe bottom thereof. From the top of the tank 2 a Vlpipe line l leads to a compressor i and in the line l the gas may bemaintained at a temperature of approximately 20 F. and under pressuresof 125 to 150 pounds per square inch. After being sub-Y jected to theaction of a compressor the gas leaves i the latter through a pipe line 6at, forexample,

a temperature oi' 300 F. and at a pressure of approximately 1000 poundsper square inch. The gas is forced by way of the pipe line 6 into a bankof preheating tubes 1 which are positioned I within the stack outlet lof a heater or still 9.

From the preheating tube 'i the gases flow by l way of the line Il to ahorizontally arranged row of tubes Il placed inthe roof of thecombustionr chamber I2 of the heaterwhich tubes arel subsired typeis'situated in the lower portion of the chnmber'l2 and'abridge wallllarranged transversely inlthe setting of the heater separatesthe chamber|21 from atube chamber i5, the latter being in communication with theoutlet `2 by way j of the opening Il. Arranged within the tube.

chamber I i lisa. bankof tubes i1 which communicate with'the tubes Il bymeans` of the pipe Il. Thus the gases after'leaving .the compressor larel subjected to the heater the still by being' passed. rst.' throughthe preheatingV tubes. l',

thence through the roof ytubes. Il and then through the ilnal bank -oitubesll and it is within t 40 the tubes II and l1 especiallythat thedesired polymerization reactions take place.

The typical polymerization reaction is an exothermic -one and thereforemeans must be provided vfor Acontrolling this exothermic reaction.

Bypassingjthe gases within the tubes comprising the reaction sections Iland. I1 parallel to the iiow ofthe iiue gases I secure this desiredresult.

Initially, theV temperature of the hydrocarbon gases within the reactiontubes will be below the so temperature of the flue or furnace gases,4and there will be some slight tendency for heat to be absorbed in thefirst passes or tubes. of the reaction sone. As the reaction progresses,however, heat will be given loi! in a consistentlyl insscreasingquantity, and the temperature of the reacting gases will rise untiltheir temperature is equal to or above the temperature of the iur'-,r

nace or'ue gases surrounding lthe tubes. Ina.:-`

much as a very high temperature in these-reyau acting hydrocarbon gasesis undesirable, becauseV of the attending formation of tars andvfreecar-l bon, it is highly desirable that 4the ltemperature 'y of thereaction should not go appreciably above 1000 l". Since the `flue gasesin this portion of Athe furnace, um uw say, inthe chamber is,

will be considerably below this temperature they will act as a coolingmedium preventing the reaction temperature of the hydrocarbon gases fromy going beyond desired limits. 'I'he apparatusde-V 1o scribed thereforegives isubstautnuy automneL control of the temperature of reaction. Ex,pressed in other words, the apparatus` provides for maintaining auniform temperature vof reaction in exothermicreactions of hydrocarbonjected in particular to the radiant heat developed j within the chamberI2. "A burner'il of any de- The tube bank i1 is in direct communicationwith an outlet pipe line i9 which leads to a cooling coil unit 20 whichreduces the temperature of the gases and polymers to approximately 100F. From the cooling unit 2l the gases and liquids flow by way of a pipeline 2| to a second accumulator tank 22 which is internally baffled asat 22. The topjof theV tank 221s connected with a gas outlet line 24by'which the permanent gases are removed from the system. The line 24may be provided with a pressure reducing valve 25 and leads'to'a gastank. burner, such as a "burner l2, or other zone of storage orutilization.

The` liquids accumulate in the bottom of the tank 22 andare withdrawnbyway of a pipe line 26 provided with a pressure releasing valve 26'.The

end of the line 2l contains a plurality of branches 21 which enter astabilizing tank 2l which is adapted .to weather or stabilire theliquids by removing therefrom excessively volatile compounds in the formof vapors or'gases, particularly pro- 'L pylene or butylenefractionsjthe latter being discharged from the top vof the tank 2'2byway of a pipe line 22 whichleads to thel pipe `-line i.A providing forthe re-'circulationpof such volatiles through the system and repeatedItreatment thereof. The bottom of the tank 28 may be provided'with alie-boiler'rmilv 20 and withadrawoif line 3i leading toa storage tank orthelike 22. The above system provides a practical and Y economicalmethodand means for treating hydrocarbon gases so as to obtain therefrom themaximum quantity of liquid suitable for use .as wonnen v eliminates aloss in liquidmotor fuelwhich now normallyl obtains injpresent systems:utilizing gases discharged from compressor recovery sys- Particularly,the present yinvention 'l tems' of `oil crackingv Plants. ,Invapor-phase f methods of'cracking oil, cracking temperatures in excessof 1000" F. arefrequentlyutilized. These lcracking temperatureshave beenfound to produce motor fuels having many advantageous characteristicswhich vrender the fuels peculiarly suitable for modern internalcombusvapor-phase system. are. correspondingly` increased.` Infact, Ihaveffound that by the employment ofthe present invention in connectionwith a vapor-phase cracking system the total :quantity of liquid vmotorfuel Y recovered .from y`algiven amount of charging stock entering thesystem exceedsthe normal vrecovery of liquid motor fuel obtained `fromystandard types of liquid phase cracking systems. ,The pr'esentinvention provides for a method of polymerization which functionscontinuously and without any appreciable carbon formation. Further, theoperation of the system issubstantially automatic.

'Ihis applicationis a continuationin part of. ymycopenlingl applicationSerial'No.. 333,756 iiled vJanuaryv 19, 1929, whichyhas eventuated intoPatent 'Nog 2,028,886. Whatis claimed is: .y

1. Ihe method of polymerizing unsaturated vapor phase cracking oi."hydrocarbon oils, which t comprises passing such gases, in theabsenceo!`added hydrogen. af heated `v`reactionlii'nie` i of `restrictedcross-sectional and ltherein C heatingz said gases `to a temperaturebetween ap- `une condensed liquids by removing therefrom `temperaturesandpressures.

`a. The und er hydrocarbon permanent `gases obtained from unrestrictedcross-sectional areafandtherein f gases;"`to a temperature between u lapproximatelyaoil" F. andapproximately 11000? i lyhile a pressure o! 300to1000 pounds per square inch' to "produce"exotlfiermicf.. poly-.

mediation reaotiiina then cooling `and condens` thel products of `suchreactions without subthecondensed liquids from the llean gases,sta

turningto thefreactionzone "the gases produced by such stabilisation.

` hydrocarbon d permanent gases-obtained `from f comprises passing suchgases, in I` theabsence of` added hydrogen, thrua heated reactionsone ofrestricted cross-sectional'area and therein heat-` ing said gasestoatemperaturebetween approxi-p; p mately 800 F. andapproximatelyl000\.F.1`while p vunderapressure *of 300to 1000 pounds `per ,squareinchV toty produce exothermic polymerizal tion reactions; then-coolingand condensing the i productsofsuchvreaotions without substantial I urelease ofpressure thereon, separating the con-` wldensed liquids fromthelean gases,iand stabilize` 50 inglthecondensed liquids `by removingthereratedV hydrocarbon permanent gases when `initially `enteringthe@reaction zone being brought o, intoheat exchanging' relationshipWith-relatively"` high temperature furnace gases and Vwhenleaving saidreaction zone into heat exchanging relationshipV with relatively lowtemperature furnace gases.

4. The method of polymerizing unsaturated Y o hydrocarbon permanentgases obtained from vapor phase cracking of hydrocarbon oils, whichcomprises passing such gases, in the absence of added hydrogen, thru aheated reaction zone of restricted cross-sectionalarea and therein heatui 65 ingtsaid gasesto a temperature between approximately 800 F. andapproximately 1000 F. while under a` pressure of 300 to 1000 pounds persquare inch to produce exothermic` polymerization reactions, thencooling and condensing the 70 products or' such reactions withoutsubstantial those components which gases at ordinary l "polymerizing`vapor phase 'cracking oi 'hydrocarbonoils`, which comprises passingsuchgases."inltheabsence lof i addedhydrogen, thru aheated reaction`stantialfrelease' `of pressure thereon, separatingtheflcondensedliquids by removing therefrom those components whichfaretgasesatordinary temperatures and pressureaand reu from Ythose i componentswhich are gases at l ordinary temperaturesfand pressures.saidmnsatusaidlexothermic reactiontemperatures otitbc hydrocarbongaseswithin said reaction loneby subjecting the outlet portions `oi saidsone to temperatures t lower than the finlet portions 5. In a processiorobtaining low boiling point "hydrocarbon liquid polymerspredominantly of the motor fuel 'range from oleiinic hydrocarbonA gases,`continuously compressing said gases toa, pressure o! the orderot4500to1000 pounds per square inch," subsequently. said gases under suchpreasureyin `the absence-of added,`

. hydrogen, through an elongated passageway ot f restricted crosssectionalarea while heating the gases therein to a temperaturesuiiicient to` initi ate polymerization `of said gases, then passingsaid gasesthrough a reaction zone under said pressure; maintaining. thevgases `in said zone lfora penedbf time sumeient te obtain an exetnermief `reaction and at temperatures between '100 andv 10001;F.and preventingexcessive rise in temperature'in said reaction zone, and then separat-Ving low boiling point liquid polymers so produced. y 6. I/nV a' processz for obtaining Vlow-boiling point hydrocarbon yliquid polymers of` themotor `fuel hydrocarbon gases, continuously `compressing said gases to1a pressure `1betweerr5`00 and 1000 pounds per square inch, subsequentlypassing said gases under auch pressure, in the absence o!` addedhydrogen, through `a passageway oi' restricted cross sectional lares.deilninga primary sone while f heating the gases therein fto atemperature sufilcientV toinitiate polymerization ot said gases.

, p Y i t then assin `said:` assundesuch` ssure `3."llhe` methodoffpolymerizing `unsaturated p g g e r me range from predominantlyunsaturated oleiinic t.

through a secondary zone while maintaining `the j' gases in said4secondary zone at a temperature between "100 and 1000 to obtain anexothermic reaction under controlled thermal conditions, and

mersso produced. .i t.

"7:"In a process `for-obtaining low boiling point then separatingl'owboiling` point liquidpolyhydrocarbon liquid'fpolymerspredominantlyoi' the motor fuel rangeA from oleinic hydrocarbon gases,Vcontinuously compressing `said gases tozan operative pressure in,excess of 500 poundsxper in the absence ot added hydrogem through apassageway of" restricted@cross-sectional area `while heating the gasestherein to a temperature su!- cient to initiate polymerization of saidgases,`

then passing said gases.` through` a main reaction zone under saidpressure and maintaining the, gases in` said zone `for a `period `of"time "suiiicient to obtain an exothermicreaction and at temperaturesbetween 'i00fand 1000 F. without insquare inch but below an-u'nduly.high inoperative pressure, passingsaid gases under such pressure,

troducing any` extraneous heat into the zone,

and then separating low boiling liquid polymers so produced.-

8. In a process for obtaining low boiling.` point inch,znibsequentlypassing said gases under suchl measure, in the .absence oi addedhydrogen, i. through a primaryzone'whileheating the gases 1700 and1000F'., and then separating klow boil- 700 1000 l". without introducingany extraneous heat into the zoneand then separating v.

low boilingpoint liquid polymers so produced.

9. In a process for obtaining low boilingpoint l cross sectional areawhile heating the gases thereintoa temperature sumcient to initiatepolynsrlntionotsaidgaseathenpassingsaidgases through a reaction zoneunder said pressure while maintaining the gases in said zone for aperiod of time sumclent to obtain an exothermic reaction and attemperatures between 800 and 1000 F. without introducing any extraneousheat into the sone, and then separating low boiling point liquidpolymers soproduced. 'f i 10..In a-process for obtaining low boilingpoint hydrocarbon liquid polymers'of the motor fuel range fromVpredominantly unsaturated. oleilnic hydrocarbon gases, continuouslycompressing Asalcl gases to a pressure between500 and 1000 pounds persquare inch, subsequently passing said such-pressure, in the absence ofadded'hydrogen,v through a passageway of restrlcted crosssectional"areadening a primary Alionewhileheating the gases therein to atemperature sumclent. toinitiate polymerization of said gases,thenpassing said gases under said pressure and at a temperature between700 F. and V1000". F. through a secondary zone to obtain an exothermicreaction,` maintaining anV operativev temperature of'exothermicreactionin, said' secondary zone atsaid pressure, and then sepa-y rating lowboiling point, liquid-poiymersso pro-r gases. continuouslycompressingrsaid gasesto a pressure between 500 and 1000 pounds per square thereinto a temperaturesumcient to initiate polymerization of said gases, thenpassing said gases through asecondary zone protected against excessiveheating and cooling, maintaining said gases in said secondary zone, atsaid pressure and for. a; period of time suiiicientv4 to obtain anexothermic reaction and attemperatures between ins liquid polymers soproduced.

12. A continuous process for producing liquid hydrocarbons predominantlyof the motor fuel range from hydrocarbon gases which comprises heatinghydrocarbonl gases in the absence of added, hydrogen. containingsuillcient unsaturated hydrocarbons to give an exothermic reac- -tionaccompanied by rise in temperature under the conditions of temperatureand pressure herein specified in a heating zone, maintaining said gases`in a reaction zone at a pressure between 300 and 1,000 pounds r squareinch and at a temperature not substantially in excess of 1,000 P., butsuiiicient to promote the exother-l mic reaction of the gas, by the heatof reaction, for a period of time sumcient to convert a substantialproportion of the gases to normally liquid hydrocarbons, and separatingthe liquid and geous products of the reaction.

13. Process in accordance with claim 12 in which the gases aremaintained between 500 and 1.000 pounds per square inch and at atemperature between 800 and 1,000 F. in the absence of added hydrogen.

14. A continuous non-catalytic process for the conversion of gasescontaining suilicient oleiinic hydrocarbons to give an exothermicreaction accompanied by rise in temperature under the conditions. of'temperature and pressure herein specified which comprises heating thegases under superatmospheric pressure vin the. absence of added hydrogento enable them to attain a temperature in excess of 800 F. but notsubstantially in excess of 1,000 F., maintaining the gases in a reactionzone at a pressure between 300and 1,000pounds per square inch, and above800 F. but notgsubstantially above 1,000" F., by the exothermic heat ofthe reaction, for a. period'oi' time sufiicient to convert a substantialportion ofthe gases to liquid lwdrocarbons boil-A ingrwithin thegasolinerange, and. separating the liquid from the gaseous conversion products.

15. A continuous process for converting hydrocarbon gases rich vinoleilne gases into hydrocarbons of higher rmolecular weight whichcomprises' heating said gases in a restricted stream to a temperaturesumcient to initiate polymerization of the oleilnic hydrocarbons bytemperature and pressure suitable for polymerization of said gasesthrough a reaction zone in heat exchange relation with combustion gasesat a lower temperature than the temperature of the reacting gases`whereby to prevent. excessive rise of temperature dueto the exothermicreaction of said gases, cooling the reaction products and separating thegases from the remaining products.`

` CARY R. WAGNER.

means of `hot products of combustion, then vpassing the reactingl gasesunderconditions of

